1. Field of the Invention
The present invention relates to a storage system and a snapshot configuration migration method.
2. Description of the Related Art
A storage controller, which configures a storage system, provides a host computer (hereinafter, host) with a relatively large capacity storage area. The storage controller, for example, is capable of creating a redundant storage area by configuring storage devices, such as hard disk devices, based on RAID (Redundant Array of Independent Disks). The host utilizes a logical volume disposed on top of this redundant storage area.
Now then, an existing old storage controller may be replaced by a new storage controller due to device obsolescence or for maintenance purposes. In this case, the data managed by the old storage controller will be migrated to the new storage controller (see Japanese Patent Laid-open No. H11-184641).
Furthermore, a snapshot function, by which a data image of a volume at a prescribed point in time can be managed by managing the volume update location and pre-update old data, is also known (see Japanese Patent Laid-open No. 2007-213345).
When the old storage controller is replaced with a new storage controller, it is not enough to simply migrate the data managed by the old storage controller to the new storage controller. When the snapshot function is being used in the old storage controller, the configuration related to the snapshot must also be migrated from the old storage controller to the new storage controller.
Now the snapshot management information and such stored in the old storage controller could be transferred to the new storage controller, but a special mechanism for migrating the snapshot configuration would have to be added to both the old storage controller and the new storage controller in this case, making the migration process complicated.
Storage controllers have grown quite popular in recent years, and the migration from an old storage controller to a new storage controller using a less expensive and simpler configuration is required. However, a migration method according to the prior art requires a special dedicated function for passing the snapshot configuration on to the new storage controller, making it impossible to respond to market demands.